1018 Marvels of the Universe 
animals act and react upon one another. Briefly, it is assumed that time was when this whitening 
did not take place, and that, in consequence, when the snows of winter fell, the garments of fur 
and feather of every inhabitant of the region showed up as conspicuous dark blotches against their 
white setting, and thus became an easy mark for every raptorial bird and beast in the neighbourhood ; 
and similarly, of course, the prowling enemy was descried by his intended victim. Now if this 
interpretation be correct, then, some of my readers will say, a very different result should have 
followed. In a word, a season or two should have rid the preyed-upon of their enemies, and per- 
manently. They must have died of starvation, for being dark, they would have been detected 
before they could get within range of the victim, and thus only by the merest accident would they 
NORTHERN ANIMALS IN SUMMER DRESS. 
The Mountain Hare, Grouse and Ptarmigan are here shown in summer fur and plumage whose colours harmonize with 
those of their surroundings. 
ever get a meal—that is to say, when they caught a victim by surprise. Thus, there would be no 
need for the whitening process. 
But suppose these imaginary circumstances be reversed: that is to say, that the carnivorous 
types were the first to assume a white garb at the approach of winter. Then, unless their 
victims could respond in like manner they would speedily be wiped out. That natural selection 
alone could not have originated these white vestments goes without saying; and we must 
assume, therefore, that this factor seized, as it were, upon those individuals which, during some 
ancient past, tended to suffer some physiological check at the fall of the temperature ushered 
in by the advent of autumn, whereby the formation of the normal pigment for the coloration of 
the fur or feathers, as the case may be, was checked, more or less completely. Such individuals 
would at once secure an advantage over those which were not thus affected. The latter, from their 
conspicuousness, would be killed off; the whitening individuals would survive and hand on their 
inherent peculiarities to their offspring. 
